CN103248983A - System and method for a PCM interface for a capacitive signal source - Google Patents
System and method for a PCM interface for a capacitive signal source Download PDFInfo
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R3/00—Circuits for transducers, loudspeakers or microphones
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K7/00—Modulating pulses with a continuously-variable modulating signal
- H03K7/08—Duration or width modulation ; Duty cycle modulation
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M3/00—Conversion of analogue values to or from differential modulation
- H03M3/02—Delta modulation, i.e. one-bit differential modulation
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M3/00—Conversion of analogue values to or from differential modulation
- H03M3/30—Delta-sigma modulation
- H03M3/39—Structural details of delta-sigma modulators, e.g. incremental delta-sigma modulators
- H03M3/412—Structural details of delta-sigma modulators, e.g. incremental delta-sigma modulators characterised by the number of quantisers and their type and resolution
- H03M3/422—Structural details of delta-sigma modulators, e.g. incremental delta-sigma modulators characterised by the number of quantisers and their type and resolution having one quantiser only
- H03M3/424—Structural details of delta-sigma modulators, e.g. incremental delta-sigma modulators characterised by the number of quantisers and their type and resolution having one quantiser only the quantiser being a multiple bit one
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R19/00—Electrostatic transducers
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R19/00—Electrostatic transducers
- H04R19/005—Electrostatic transducers using semiconductor materials
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R19/00—Electrostatic transducers
- H04R19/01—Electrostatic transducers characterised by the use of electrets
- H04R19/016—Electrostatic transducers characterised by the use of electrets for microphones
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R19/00—Electrostatic transducers
- H04R19/04—Microphones
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2460/00—Details of hearing devices, i.e. of ear- or headphones covered by H04R1/10 or H04R5/033 but not provided for in any of their subgroups, or of hearing aids covered by H04R25/00 but not provided for in any of its subgroups
- H04R2460/03—Aspects of the reduction of energy consumption in hearing devices
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R2499/00—Aspects covered by H04R or H04S not otherwise provided for in their subgroups
- H04R2499/10—General applications
- H04R2499/11—Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's
Abstract
The present invention discloses a system and a method for a PCM interface for a capacitive signal source. In accordance with embodiment, a method includes amplifying signal provided by a microphone to form an amplified signal. The method also includes converting the amplified signal into a frequency-based signal having a frequency dependent on an amplitude of the amplified signal. The frequency-based signal is converted into a pulse code modulated bitstream.
Description
Technical field
The present invention relates generally to semiconductor circuit and method, more specifically, relates to the pulse code modulation (pcm) at the capacitance signal source.
Background technology
Audio speaker is generally used for multiple consumer application, for example mobile phone, digital audio transcripter, personal computer and TeleConference Bridge.Especially, low-cost electret capacitor type loudspeaker (ECM) is used for the application of the cost sensitivity of large-scale production.The ECM loudspeaker generally includes the film of electret, and it is installed in the little encapsulation with sound port terminal and electric lead-out terminal.Electret is attached to vibrating membrane or is made up of vibrating membrane itself.Most of ECM loudspeakers also comprise the preamplifier that can be interfaced to the audio front end amplifier in the target application (for example mobile phone).The loudspeaker of another kind of type is Micro Electro Mechanical System (MEMS) loudspeaker, and it can be implemented as pressure sensitive film spare, and wherein pressure sensitive film spare can be etched directly in the integrated circuit.
In the application that the MEMS loudspeaker is realized with Small Form Factor (for example smart mobile phone or panel computer) encapsulation, use the audio interface of utilizing minimum pins.A this interface is pulse code modulation interface (PCM), and its generation has and the proportional pulse duration of audio signal of MEMS loudspeaker sensing or the PCM signal of impulse density.Small Form Factor use also normally lower powered, for the battery operated device of power consumption sensitivity.In order to keep long battery life, minimize the micropkonic power consumption of MEMS and its board level audio interface, thereby keep battery life.
Summary of the invention
According to execution mode, a kind of method: comprise that the signal that loudspeaker is provided amplifies, thereby form amplifying signal.This method also comprise with amplifying signal convert to frequency depend on amplifying signal amplitude, based on the signal of frequency.Should convert the pulse code modulation bit stream to based on the signal of frequency.
Set forth the details of one or more execution modes of the present invention in the drawing and description below.According to specification, accompanying drawing and claim, other features of the present invention, target and advantage will become apparent.
Description of drawings
For a more complete understanding of the present invention and advantage, now by reference to the accompanying drawings with reference to following specification, in the accompanying drawings:
Fig. 1 a to Fig. 1 b shows loudspeaker interface system according to the embodiment of the present invention;
Fig. 2 a to Fig. 2 d shows the voltage controlled oscillator for exemplary loudspeaker interface system;
Fig. 3 a to Fig. 3 d shows frequency for exemplary loudspeaker interface system to the PCM transducer;
Fig. 4 a to Fig. 4 b shows the loudspeaker interface system according to another embodiment of the present invention;
Fig. 5 a to Fig. 5 c shows the voltage time transducer for example system;
Fig. 6 a to Fig. 6 b shows time for example system to the PCM transducer; And
Fig. 7 shows exemplary loudspeaker module.
Embodiment
Formation and the use of present preferred implementation at length are discussed below.Yet, should be appreciated that the concept that the invention provides many suitable inventions that can in multiple concrete environment, realize.The embodiment of discussing only is formation and uses illustrative concrete mode of the present invention, and unrestricted protection scope of the present invention.
To the present invention be described about the execution mode in the specific context, just at interface system and the method for capacitance signal source (for example MEMS or electret capacitor type loudspeaker (ECM)).Yet the present invention also can be applicable to circuit and the system of other types, for example audio system, communication system, sensing system and be interfaced to the other system in high impedance signal source.
Fig. 1 a shows the example integrated circuit (IC) 100 that is configured to be coupled to MEMS loudspeaker 102, and wherein, this MEMS loudspeaker is shown in broken lines to show that loudspeaker 102 needn't be included on the IC100.Yet in some embodiments, loudspeaker 102 also can be included on the IC100.Hi an alternative embodiment, replace MEMS loudspeaker 102, can use other loudspeaker-type, for example the capacity sensor circuit of ECM loudspeaker or other types.
IC100 has amplifier 106, voltage-frequency converter 108 and frequency-PCM transducer 110.Amplifier 106 has one or more levels, and the output that is coupled to the MEMS loudspeaker 102 of IC100 via input pad 114 is amplified.In some embodiments, amplifier 106 may be embodied as, for example, the common trial application number of submitting on July 14th, 2,011 13/183 that is entitled as System and Method for Capacitive Signal Source Amplifier, described in 193, this application all is hereby expressly incorporated by reference.Replacedly, can realize amplifier 106 according to technology as known in the art.
In some embodiments, for example in utilizing the micropkonic execution mode of MEMS, bias voltage maker 104 self provides bias voltage at pin 116 places for loudspeaker 102.In some embodiments, depend on specific loudspeaker and system's implementation, this bias voltage can be approximately between 3V and the 60V.Replacedly, can use other voltage ranges.In further execution mode, if if loudspeaker or transducer 102 do not need bias voltage or provide required bias voltage in other somewheres, can omit bias voltage maker 104 so.Should further understand, in replaceable execution mode, can utilize not only parts and/or not only IC realize parts on the IC100.
Voltage-frequency converter is converted to frequency signal 118 with the output voltage 120 of amplifier 106, and frequency-PCM transducer 110 converts frequency signal 118 to the PCM signal, is used for transmitting at port one 12.In some embodiments, frequency signal 118 is digital pulse signals, and this signal has the frequency that is directly proportional or is inversely proportional to the output voltage 120 of amplifier 106, as shown in Fig. 1 b.Replacedly, signal 118 can be that variable frequency sine curve, square wave or frequency are based on other waveforms of the output voltage 120 of amplifier 106.In further replaceable execution mode, voltage-frequency converter 108 can production burst density modulation waveform, and it has the impulse density that is directly proportional or is inversely proportional to the output voltage 120 of amplifier 106.
Voltage-frequency converter 108 can be realized by the voltage controlled oscillator 109 as shown in Fig. 2 a.VCO109 can utilize circuit as known in the art and method to realize, for example, utilizes the oscillator of ring oscillator, relaxation oscillator or other types.In some embodiments, the input of VCO109 and/or output can be differential signals.For instance, Fig. 2 b shows the CMOS ring oscillator 202 with a plurality of inverter stages that can use in the example system implementation.For example, by changing the frequency that supply voltage VDD can control ring oscillator 202.
Fig. 2 c show can be used for the realization example voltage-frequency converter, utilize the inverter stage 212 of the hungry types of three electric currents, 214 and 216 ring oscillator 220.Replacedly, can use more or less level.The frequency of ring oscillator 220 is proportional with the voltage VCTRL that is applied to nmos device N208.Along with the voltage on the grid of N208 increases, the electric current by transistor N208, P206, P204 and N210 correspondingly increases.The electric current that increases to inverter stage 212,214 and 216, thereby increases the frequency of oscillator 220 via transistor N212, P212, N214, P214, N216 and P216 mirror image.
In replaceable execution mode, relaxation oscillating circuit 230 can be used for the realization example voltage-frequency converter.Relaxation oscillator 230 has operational amplifier 232 and the capacitor C234 that the integrator structure of serrated signal of generating 235 couples.Oscillator 230 also has the output of monitoring operational amplifier 232 and the comparator 234 of generated frequency modulated pulse signal 236.The frequency of oscillator 230 depends on the voltage Vc of the input that is applied to operational amplifier 232.Transistor Q238 can be implemented as cmos device in some embodiments.Should be appreciated that the VCO circuit of describing among Fig. 2 a to Fig. 2 d only is the particular instance of oscillator that can be used for many types of realization example system.
In execution mode, utilize the sigma-delta-converter 111 as shown in Fig. 3 a can realize frequency-PCM transducer 110.Utilize in this area various known sigma-delta-converter circuit and method can realize sigma-delta-converter 111.
In example frequency-PCM transducer, by being counted, can measure by acquired information the zero cross point of output signal in the given reference time.Average frequency in this count results and this given reference time is directly proportional.The all right quantitative information of this measurement, thus the counting with integer zero cross point generated.In some embodiments, by being cost with the high power consumption digitizer of measuring quantization error is selected high oscillation frequency and/or by utilizing additional period to reduce this quantization error.In one embodiment, save power by the using noise shaping technique, keep " bigger " quantization error simultaneously.A method that realizes this characteristic is to guarantee that the counting that zero cross point is carried out can not stop at any time, but at fixed time moment estimation Counter Value, so frequency output in time is the poor of two continuous counter values.This method provides the shaping of single order quantizing noise.
Fig. 3 b shows the frequency-PCM transducer 302 according to another execution mode.Replace utilizing single counter to estimate the single output of VCO, use the heterogeneous character of ring oscillator 304.In execution mode, be loaded into register 306 and 308 by the continuous state with all ring oscillator outputs, estimate a plurality of outputs of ring oscillator 304.The difference and utilization summation 312 nodes that are generated the oscillator state of these samplings by XOR gate 310 are sued for peace.The difference of two sample states (being generated by the XOR function) is directly proportional with instantaneous frequency.And, this quantization error of single order noise shaping.Should be appreciated that the circuit of Fig. 3 b just can be used for an example of the many possible example frequency-PCM transducer of example system.
In execution mode, the output of frequency-PCM transducer 110 is the individual bit pulse code modulation signals 112 as shown in Fig. 1 a.In replaceable execution mode of the present invention, by utilizing clock signal frequency modulated signal 118 is sampled to realize frequency-PCM transducer 110, thus and combine digital Signal Regulation generation PCM signal 112.In another embodiment, can be coupled to loudspeaker from the feedback signal of frequency-PCM transducer 110, thereby improve systematic function.
Fig. 3 c shows frequency-PCM transducer 320 according to another implementation of the invention, and wherein, digital sigma-delta noise reshaper is used for the multiple bit digital data transaction is become the monobit digital data.Frequency-voltage converter 320 has asynchronous counter 322, sampler 324, difference block 326 and serializer piece 328.In execution mode, the output of difference block 326 is the many bit outputs of n bit.Serializer piece 328 can utilize digital sigma-delta-converter to realize.At this moment, the result of VCO analog digital conversion can be that multi-bit is according to stream.
In further execution mode, utilize the ADC based on voltage/frequency in the feedback arrangement to realize frequency-PCM transducer.In this embodiment, the many bits output of frequency measurement piece is serialized as an output stream, then it is fed back to analog input end.Difference offers analog filter, and the output of analog filter is coupled to voltage-frequency converter.This structure is called as " based on the sigma-delta ADC of VCO " in this area, as shown in Fig. 3 d.Here, the sigma-delta ADC340 based on VCO has loop filter 342, VCO344 and frequency-PCM transducer 346.In execution mode, the frequency-output of PCM piece 346 feeds back to the input of loop filter 342.In execution mode, frequency-PCM piece 346 comprises serializer.
Fig. 4 a shows the example integrated circuit 130 that is configured to be coupled to MEMS loudspeaker 102.Except at the PCM of output 112 signal be by voltage-time converter 132 be then time-PCM transducer 134 generated, integrated circuit 130 was similar to the integrated circuit shown in Fig. 1 a.In execution mode, voltage-time converter 132 converts the output 120 of amplifier 106 to time modulation signal 136.Time-PCM transducer 134 then convert time modulation signal 136 to PCM signal 112.In execution mode, time modulation signal 136 can be the pulse-width signal as shown in Fig. 4 b.Herein, pulse width T
PWBe directly proportional with the output voltage 120 of amplifier 106.As shown in Fig. 4 b, along with the voltage increase of output voltage 120, pulse width T
PWReduce.Replacedly, T
PWCan be along with the increase of the output voltage 120 of amplifier 106 and increase.
According to execution mode, voltage-time converter 132 can utilize the pulse width modulator 133 as shown in Fig. 5 a to realize.Pulse width modulator 133 can utilize as known in the art for the circuit that generates pulse-width signal and method realization.In some embodiments, pulse width modulator 133 can utilize different circuit to realize.
Fig. 5 b shows the pulse width modulator 500 that can be used for embodiments of the present invention.Herein, triangular signal or serrated signal 502 as a reference and utilize comparator 504 to compare with input signal 120, thereby generate pwm signal 136.In one embodiment, pwm signal 136 is continuous time, discrete amplitude signal, and wherein the timing information of input signal is encoded to the poor of high time and low time.In interchangeable execution mode, can use other circuit and method, for example, not provide the self-oscillation PWM generator input of reference signal.
Replacedly, utilize diclinic rate technology can realize pulse width modulator 133 by the dual slope converter 520 as shown in Fig. 5 c, the time is as the conversion reference in Fig. 5 c.Herein, at a certain preset time of t
uVin quadratures to input signal.After this, utilize given known reference voltage discharge integrator, up to being output as zero.Measure the spent time t of discharge integrator
dIn execution mode, t
dBe directly proportional with input voltage vin.
In execution mode, utilize sigma-delta-converter 135 time of can the realizing-PCM transducer 134 as shown in Fig. 6 a.Utilize various sigma-delta-converter circuit as known in the art and method can realize sigma-delta-converter 135.In execution mode, the output of frequency-PCM transducer 110 is the single-bit pulse code modulation signals 112 as shown in Fig. 4 a.In replaceable execution mode of the present invention, can realize frequency-PCM transducer 134 by utilizing clock signal sampling time modulation signal 136, thus and combine digital Signal Regulation generation PCM signal 112.In another embodiment, can utilize delay cell to generate PCM signal 112.For example, in one embodiment, time-digital quantizer has the delay cell of a plurality of cascades.During operation, between the edge of a pulse, measure the delay cell number that pulse is passed through.
Fig. 6 b shows exemplary time-digital quantizer 600, time-electric pressure converter 602 and serializer 604 that this time-to-digit converter utilization can use digital sigma-delta-converter to realize.Herein, by measuring the high time, measure the low time and calculate the high time and the difference of low time can Digital PWM signal 136.Replacedly, if PWM has constant given frequency, can measure high time or low time so, and can utilize given frequency to calculate corresponding low time or high time.In execution mode, utilize clock counter or utilize time-numeral (TDC) transducer can carry out this time measurement, for example, under the situation of very short pulse.In some embodiments, utilize sigma-delta noise reshaper (for example serializer 604) to convert the output of TDC to the single-bit form from many bit format.
Fig. 7 shows loudspeaker module according to the embodiment of the present invention.If comprise IC100 as the described loudspeaker module of execution mode herein, and be coupled to MEMS loudspeaker 102.Loudspeaker 102 and IC100 are arranged in the encapsulation 150 with port one 52 and PCM output port 154.In replaceable execution mode of the present invention, IC100 can utilize different execution modes to realize, for example, and the IC130 as shown in Fig. 4 a.In execution mode, encapsulation 150 can utilize audio amplifier to implement, and wherein, the MEMS loudspeaker is installed in the have sound port top of printed circuit board (PCB) (PCB) in (for example hole).Application-specific IC (ASIC) with exemplary circuit of describing herein is installed in the micropkonic position of contiguous MEMS.Utilize metal cap to cover the assembly that produces, it is sealed to PCB in one embodiment.Replacedly, can use other encapsulated types.
According to execution mode, method comprises amplifies the signal that loudspeaker provides, thereby forms amplifying signal.This method also comprises and converts amplifying signal to based on frequency signal, should depend on the amplitude of amplifying signal based on the frequency of the signal of frequency.To convert the pulse code modulation bit stream based on the signal of frequency to.In some embodiments, amplify the signal that is provided by loudspeaker and comprise the micropkonic output of amplification MEMS.
In execution mode, will convert signal based on frequency to through amplifying signal and comprise and make the input that is coupled to voltage controlled oscillator through amplifying signal.In some embodiments, frequency signal being converted to the pulse code modulation bit stream comprises and makes the input that is coupled to sigma-delta-converter based on the signal of frequency.
In execution mode, method comprises the signal that amplification is provided by loudspeaker, thereby forms amplifying signal, converts amplifying signal to timing based on the time-base signal of the amplitude of amplifying signal, and converts time-base signal to the pulse code modulation bit stream.In some embodiments, amplify the signal that is provided by loudspeaker and comprise the micropkonic output of amplification MEMS.In some embodiments, convert amplifying signal to time-base signal and comprise the input that makes amplifying signal be coupled to the pulse width modulator in some execution mode, convert time-base signal to the pulse code modulation bit stream and comprise the input that makes time-base signal be coupled to sigma-delta-converter.
According to another execution mode, circuit comprises voltage-frequency converter (its input is configured to be coupled to loudspeaker), and frequency-PCM transducer (its input is coupled to the output of voltage-frequency converter).In some embodiments, circuit also comprises loudspeaker, and it can be MEMS loudspeaker or other loudspeaker-type as known in the art.In some embodiments, voltage-frequency converter can utilize voltage controlled oscillator to realize that frequency-PCM transducer can comprise sigma-delta-converter.
According to another execution mode, circuit comprises voltage-time converter (its input is configured to be coupled to loudspeaker), and time-PCM transducer (its input is coupled to the output of voltage-time converter).In some embodiments, this circuit can also comprise loudspeaker, utilizes MEMS loudspeaker or other loudspeaker-type as known in the art to determine.In some embodiments, time-voltage-time converter in the PCM transducer is arranged in the integrated circuit.Voltage-frequency converter can comprise pulse width modulator, and frequency-time converter can comprise sigma-delta-converter.
According to another execution mode, the loudspeaker module comprises audio amplifier, be arranged in the loudspeaker in the audio amplifier and be coupled to the audio conversion circuit of loudspeaker output.Audio conversion circuit can comprise the voltage-frequency converter that is coupled to the loudspeaker output and be coupled to the frequency-PCM transducer of the output of voltage-frequency converter.In some embodiments, the loudspeaker module also comprises the output port of the output that is coupled to frequency-PCM transducer.In some embodiments, loudspeaker can comprise MEMS loudspeaker or other loudspeaker-type as known in the art.
The advantage of example system comprises can use very little power consumption to generate the PCM signal from loudspeaker output.And utilizing the exemplary transformation technology of (for example) VCO, pulse width modulator and/or time-digital quantizer is favourable for silicon area and power consumption, even this will be cost with extra digital circuit.This is because at small-feature-size CMOS(BiCMOS) in the technology, with regard to power dissipation and silicon area, the implementation of digital circuit is very effective.With regard to high dynamic range, some execution mode also is very favorable, and can realize that (for example) is better than the dynamic range of 100dB.
Although the execution mode of reference example has been described the present invention, this explanation is not in order to explain at limited significance.Those skilled in the art improves and combination with reference to the difference that specification will obviously be understood illustrative embodiments, and other execution modes of the present invention.Therefore, in order to make the related right requirement contain any improvement or execution mode.
Claims (21)
1. method comprises:
The signal that amplification is provided by loudspeaker, thus amplifying signal formed;
Convert described amplifying signal to based on frequency signal, the frequency of described signal based on frequency depends on the amplitude of described amplifying signal; And
Convert described signal based on frequency to the pulse code modulation (pcm) bit stream.
2. method according to claim 1 wherein, the signal that is provided by described loudspeaker is provided is comprised: amplify the micropkonic output of MEMS.
3. method according to claim 1, wherein, the signal that described amplifying signal is converted to based on frequency comprises: the input that described amplifying signal is coupled to voltage controlled oscillator (VCO).
4. method according to claim 1 wherein, converts described signal based on frequency to described pulse code modulation (pcm) bit stream and comprises: the input that described signal based on frequency is coupled to sigma-delta-converter.
5. method comprises:
The signal that amplification is provided by loudspeaker, thus amplifying signal formed;
Convert described amplifying signal to time-base signal, the timing of described time-base signal is based on the amplitude of described amplifying signal; And
Convert described time-base signal to the pulse code modulation (pcm) bit stream.
6. method according to claim 5 wherein, the signal that is provided by described loudspeaker is provided is comprised: amplify the micropkonic output of MEMS.
7. method according to claim 5 wherein, converts described amplifying signal to described time-base signal and comprises: the input that described amplifying signal is coupled to pulse width modulator.
8. method according to claim 5 wherein, converts described time-base signal to described pulse code modulation (pcm) bit stream and comprises: the input that described time-base signal is coupled to sigma-delta-converter.
9. circuit comprises:
Voltage-frequency converter, its input is configured to be coupled to loudspeaker; And
Frequency-PCM transducer, its input is coupled to the output of described voltage-frequency converter.
10. circuit according to claim 9 further comprises described loudspeaker.
11. circuit according to claim 9, wherein, described loudspeaker is the MEMS loudspeaker.
12. circuit according to claim 9, wherein, described voltage-frequency converter and described frequency-PCM converter arrangement are on integrated circuit.
13. circuit according to claim 9, wherein:
Described voltage-frequency converter comprises voltage controlled oscillator (VCO); And
Described frequency-PCM transducer comprises sigma-delta-converter.
14. a circuit comprises:
Voltage-time converter, its input is configured to be coupled to loudspeaker; And
Time-the PCM transducer, its input is coupled to the output of described voltage-time converter.
15. circuit according to claim 14 further comprises described loudspeaker.
16. circuit according to claim 14, wherein, described loudspeaker is the MEMS loudspeaker.
17. circuit according to claim 14, wherein, described voltage-time converter and described time-PCM converter arrangement is on integrated circuit.
18. circuit according to claim 14, wherein:
Described voltage-frequency converter comprises pulse width modulator; And
Described frequency-time converter comprises sigma-delta-converter.
19. a loudspeaker module comprises:
Audio amplifier;
Loudspeaker is arranged in the described audio amplifier;
Audio conversion circuit is coupled to described micropkonic output, and described audio conversion circuit comprises:
Voltage-frequency converter, be coupled to described micropkonic output and
Frequency-PCM transducer is coupled to the output of described voltage-frequency converter.
20. loudspeaker module according to claim 19 further comprises: output port is coupled to the output of described frequency-PCM transducer.
21. loudspeaker module according to claim 19, wherein, described loudspeaker comprises the MEMS loudspeaker.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US13/370,920 | 2012-02-10 | ||
| US13/370,920 US9467774B2 (en) | 2012-02-10 | 2012-02-10 | System and method for a PCM interface for a capacitive signal source |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN103248983A true CN103248983A (en) | 2013-08-14 |
| CN103248983B CN103248983B (en) | 2016-12-28 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201310052897.8A Active CN103248983B (en) | 2012-02-10 | 2013-02-18 | The system and method for the pcm interface of capacitive signal source |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US9467774B2 (en) |
| KR (1) | KR20130092479A (en) |
| CN (1) | CN103248983B (en) |
| DE (1) | DE102013202136B4 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104717591A (en) * | 2013-12-16 | 2015-06-17 | 英飞凌科技股份有限公司 | Circuit assembly and method for processing an input signal, and microphone assembly |
| CN107040831A (en) * | 2016-02-04 | 2017-08-11 | 北京卓锐微技术有限公司 | A kind of microphone for having a delay feature |
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| GB2532015B (en) | 2014-11-04 | 2018-12-26 | Cirrus Logic Int Semiconductor Ltd | Improved analogue-to-digital convertor |
| US9866938B2 (en) | 2015-02-19 | 2018-01-09 | Knowles Electronics, Llc | Interface for microphone-to-microphone communications |
| US10123103B1 (en) * | 2017-04-21 | 2018-11-06 | Infineon Technologies Austria Ag | Sigma delta modulator for sensors |
| US10158372B1 (en) * | 2017-06-20 | 2018-12-18 | Taiwan Semiconductor Manufcturing Company, Ltd. | Analog to digital converter |
| US10164653B1 (en) * | 2017-08-24 | 2018-12-25 | Taiwan Semiconductor Manufacturing Company, Ltd. | Analog to digital converter |
| KR101887824B1 (en) | 2017-09-05 | 2018-08-10 | 서울대학교산학협력단 | Analog to digital converting device and microphone including the same |
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| CN107040831A (en) * | 2016-02-04 | 2017-08-11 | 北京卓锐微技术有限公司 | A kind of microphone for having a delay feature |
Also Published As
| Publication number | Publication date |
|---|---|
| CN103248983B (en) | 2016-12-28 |
| US9467774B2 (en) | 2016-10-11 |
| DE102013202136A1 (en) | 2013-09-19 |
| DE102013202136B4 (en) | 2024-02-22 |
| KR20130092479A (en) | 2013-08-20 |
| US20130208915A1 (en) | 2013-08-15 |
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